Designers of medical instrumentation such as cardiographs face many difficult challenges in their jobs. The devices they design are expected to deliver high quality information about the electrical activity of a patient's heart to a cardiologist or other medical professional, so that a correct diagnosis of the condition of the patient's heart can be made. Unfortunately, the ECG electrodes connected to a patient usually deliver ECG data to a cardiograph that comprise not only information showing the electrical activity of the patient's head, but also electrical noise. This noise can make up most of the ECG data, and can corrupt and totally overwhelm the portion of the ECG data that contain information about the electrical activity of a patient's head. This problem is especially acute in hostile environments, such as a patient undergoing a stress or exercise test, where the noise can be quite extreme. Unless the medical instrumentation designers are successful at designing a medical instrument that analyzes this ECG data, to eliminate or reduce the effects of this noise, the cardiologist or other medical professional will find it difficult, if not impossible, to obtain information about a patient's head, such as a heart rate, that is usable in arriving at a correct diagnosis of the condition of the patient's head.